"Scent" Your Way Thin?

If you want to lose weight without counting calories or giving up your favorite foods, here’s a diet aid that takes the cake: Sensa “tastants,” sold on TV infomercials and the Internet.

These crystals (primarily maltodextrin, a carbohydrate, along with flavorings) come in two types—those that you sprinkle on sweet or neutral foods and those for salty/savory foods. By enhancing the smell and taste of food, Sensa supposedly triggers the brain’s appetite control center and speeds satiety. That is, it tricks the brain into thinking you are full. Or so the marketers claim.

A whiff of validity

Aroma plays a key role in how foods taste and in our appetite for them. So the idea that aroma may affect satiety (the feeling of fullness) is not far-fetched. Some research, including recent Dutch studies, has indeed found that certain aromas can enhance satiety and may lead to decreased food intake—though the responses depend on many factors and vary from person to person.

It’s possible, for instance, that overweight people get less sensory stimulation from food’s aromas, and thus end up eating more. Similarly, some people who lose their sense of smell (anosmia) eat more to get gratification, though others lose their appetite.

Smells fishy

But it’s a big jump to think that sprinkling Sensa on everything you eat will lead to weight loss, despite claims that the product is clinically proven. The company’s website has highlighted a large study, done by the product’s inventor, in which people using Sensa lost 30 pounds in six months.

An “independent” study supposedly had similar results. But no studies on Sensa have been published. Unpublished studies are unreliable because they have not been peer-reviewed and thus are not validated. And even if Sensa does help fill you up faster by saturating your sensory system, there’s no long-term research to know if the effects continue, or whether weight eventually returns.

Sensa is not the only aroma-related weight-loss product. ThinScents delivers a minty fragrance that, it’s claimed, increases satiety. With Slimscents, you spray the scent near each nostril before you eat. The Aroma Patch, which you put on your chest, hand, or wrist, releases a vanilla aroma. Inhale-Away is a ring you sniff to supposedly stimulate endorphins in the brain and trigger the perception of fullness. There are no published studies to back any of these products.

Dollars and scents

The idea of using aroma to control appetite is intriguing but unproven. Besides, many other factors are involved in satiety. Many people eat, for instance, not because they are hungry but because of environmental cues (such as using large plates that hold more food than you need) or psychological factors (such as eating when you are stressed or depressed). Even its maker acknowledges that Sensa won’t help people who continue to eat when they are already full.

In addition, as an aid to healthy weight loss, Sensa fails on many levels. It’s one of many pie-in-the-sky diet gimmicks that say you can eat all the unhealthy foods you want and not exercise, and still lose weight. And it costs a lot—$59 a month or over $200 for a six-month supply.

We think you should save your money. If you want to experiment on your own, see what happens when you pay more attention to the aroma of your food, fully chew each bite, and eat slowly. You might enjoy your food more and be satisfied with less. Slowing down your eating also allows signals from your stomach to reach your brain and tell you that you are full—always a good weight-loss tip.

UPDATE: December 2012 — The manufacturer has recently settled two lawsuits brought against Sensa for making false and misleading weight-loss claims and will have to pay millions of dollars in penalties and restitution to customers. Though the company admitted no liability, it must also restrain its claims and fully disclose the conditions of its automatic shipment programs before customers sign up with their credit cards.